Unique agent for cooling systems that doubles the wetting capacity of water. Rust and corrosion protection allows the use of pure water in racing or reduced levels of antifreeze in hot climates. Improves heat transfer and reduces cylinder head temperature. Use one bottle for most passenger cars and light trucks, about 3 to 5 gallons or 13.2 to 15.9 liters, vehicles with larger cooling systems should use two bottles, small cooling systems should use 1 oz (3 to 4 capfuls) per quart Compatible with new or used antifreeze (including DEX-COOL® and long life versions) to improve heat transfer of ethylene glycol and propylene glycol systems. Meets ASTM D2570 and ASTM D1384 corrosion tests for glycol-based antifreeze. Does not contain ethylene glycol.